Mapping techniques are increasingly moving away from government maps based on satellite imagery and photogrammetry to detailed localized maps. A majority of current outdoor mapping strategies are focused on the use of heavily instrumented and expensive “war driving” vans capable of collecting large amounts of data. However, the data collected by war driving vans is often proprietary and unavailable to the vast majority of mobile device users. In addition, because the use of war driving vans is limited to areas with vehicular access, many locations frequented by users cannot be mapped.
Further, attempts to use a combination of GPS receivers, cameras and online cartography tools for mapping have been limited and cumbersome. In addition, there has been no significant attempt to map the exterior of outdoor structures such as by determining the size, three dimensional (3D) shape, orientation and position of structures. The sheer number of structures makes traditional mapping techniques impractical. On the other hand, the number of such unmapped structures leaves a void that limits detail in local maps. Moreover, because structures are constantly torn down, remodeled, updated or rebuilt, keeping accurate updated maps of the exterior of outdoor structures is often cost prohibitive.
Therefore, there is a need for coherent strategies to cost-effectively acquire and maintain exterior maps of structures.